01-21-2010, 09:38 AM
Nearly 200 years after their invention, and decades after first being proposed as a method of harnessing solar energy, 60 sun-powered Stirling engines are about to begin generating electricity outside Phoenix, Ariz., for the first time. Such engines, which harness heat to expand a gas and drive pistons, are not used widely today other than in pacemakers and long-distance robotic spacecraft.
The 1.5 megawatt (MW) demonstration site, known as Maricopa Solar, is set to begin operations early January 2010, with units provided by the Arizona-based Stirling Energy Systems (SES). While 1.5 MW is only a fraction of the power that may be generated at sites SES has contracted to develop in California and Texas, spokesperson Janette Coates says this is a necessary first step in the technology’s commercialization. “It’s important for our industry to see—and our partners and investors—that we can take a small-scale plant and get it operational before we break ground on larger ones,” she says.
That's because Stirling heat engines have a reputation for being a bit impractical. First invented by Robert Stirling in 1816, the engines use a heat source to warm gas, which expands and is pushed into another chamber. When the gas cools and contracts, it flows back. The expansion and contraction pushes a piston, which in turn produces electricity.
The 1.5 megawatt (MW) demonstration site, known as Maricopa Solar, is set to begin operations early January 2010, with units provided by the Arizona-based Stirling Energy Systems (SES). While 1.5 MW is only a fraction of the power that may be generated at sites SES has contracted to develop in California and Texas, spokesperson Janette Coates says this is a necessary first step in the technology’s commercialization. “It’s important for our industry to see—and our partners and investors—that we can take a small-scale plant and get it operational before we break ground on larger ones,” she says.
That's because Stirling heat engines have a reputation for being a bit impractical. First invented by Robert Stirling in 1816, the engines use a heat source to warm gas, which expands and is pushed into another chamber. When the gas cools and contracts, it flows back. The expansion and contraction pushes a piston, which in turn produces electricity.